diff mbox

cpufreq: powernv: Remove global pstate ramp-down timer in POWER9

Message ID 1524636895-27185-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Shilpasri G Bhat April 25, 2018, 6:14 a.m. UTC
POWER9 doesnot support global pstate requests for the chip. So remove
the timer logic which slowly ramps down the global pstate in P9
platforms.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
---
 drivers/cpufreq/powernv-cpufreq.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

Comments

Viresh Kumar April 25, 2018, 6:25 a.m. UTC | #1
On 25-04-18, 11:44, Shilpasri G Bhat wrote:
> POWER9 doesnot support global pstate requests for the chip. So remove
> the timer logic which slowly ramps down the global pstate in P9
> platforms.
> 
> Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
> ---
>  drivers/cpufreq/powernv-cpufreq.c | 23 ++++++++++++++++++-----
>  1 file changed, 18 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
> index 0591874..71f8682 100644
> --- a/drivers/cpufreq/powernv-cpufreq.c
> +++ b/drivers/cpufreq/powernv-cpufreq.c
> @@ -750,8 +750,13 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
>  
>  	cur_msec = jiffies_to_msecs(get_jiffies_64());
>  
> -	spin_lock(&gpstates->gpstate_lock);
>  	freq_data.pstate_id = idx_to_pstate(new_index);
> +	if (!gpstates) {
> +		freq_data.gpstate_id = freq_data.pstate_id;
> +		goto no_gpstate;
> +	}
> +
> +	spin_lock(&gpstates->gpstate_lock);
>  
>  	if (!gpstates->last_sampled_time) {
>  		gpstate_idx = new_index;
> @@ -801,6 +806,7 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
>  
>  	spin_unlock(&gpstates->gpstate_lock);
>  
> +no_gpstate:
>  	/*
>  	 * Use smp_call_function to send IPI and execute the
>  	 * mtspr on target CPU.  We could do that without IPI
> @@ -835,6 +841,13 @@ static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
>  		kernfs_put(kn);
>  	}
>  
> +	policy->freq_table = powernv_freqs;
> +	policy->fast_switch_possible = true;
> +
> +	if (pvr_version_is(PVR_POWER9))
> +		return 0;
> +
> +	/* Initialise Gpstate ramp-down timer only on POWER8 */
>  	gpstates =  kzalloc(sizeof(*gpstates), GFP_KERNEL);
>  	if (!gpstates)
>  		return -ENOMEM;
> @@ -849,15 +862,14 @@ static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
>  				msecs_to_jiffies(GPSTATE_TIMER_INTERVAL);
>  	spin_lock_init(&gpstates->gpstate_lock);
>  
> -	policy->freq_table = powernv_freqs;
> -	policy->fast_switch_possible = true;
>  	return 0;
>  }
>  
>  static int powernv_cpufreq_cpu_exit(struct cpufreq_policy *policy)
>  {
>  	/* timer is deleted in cpufreq_cpu_stop() */
> -	kfree(policy->driver_data);
> +	if (policy->driver_data)
> +		kfree(policy->driver_data);
>  
>  	return 0;
>  }
> @@ -990,7 +1002,8 @@ static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy)
>  	freq_data.pstate_id = idx_to_pstate(powernv_pstate_info.min);
>  	freq_data.gpstate_id = idx_to_pstate(powernv_pstate_info.min);
>  	smp_call_function_single(policy->cpu, set_pstate, &freq_data, 1);
> -	del_timer_sync(&gpstates->timer);
> +	if (gpstates)
> +		del_timer_sync(&gpstates->timer);
>  }
>  
>  static unsigned int powernv_fast_switch(struct cpufreq_policy *policy,

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Michael Ellerman July 19, 2018, 6:07 a.m. UTC | #2
On Wed, 2018-04-25 at 06:14:55 UTC, Shilpasri G Bhat wrote:
> POWER9 doesnot support global pstate requests for the chip. So remove
> the timer logic which slowly ramps down the global pstate in P9
> platforms.
> 
> Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/dcb14337e0f2adb227c376e6327ef0

cheers
diff mbox

Patch

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 0591874..71f8682 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -750,8 +750,13 @@  static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
 
 	cur_msec = jiffies_to_msecs(get_jiffies_64());
 
-	spin_lock(&gpstates->gpstate_lock);
 	freq_data.pstate_id = idx_to_pstate(new_index);
+	if (!gpstates) {
+		freq_data.gpstate_id = freq_data.pstate_id;
+		goto no_gpstate;
+	}
+
+	spin_lock(&gpstates->gpstate_lock);
 
 	if (!gpstates->last_sampled_time) {
 		gpstate_idx = new_index;
@@ -801,6 +806,7 @@  static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
 
 	spin_unlock(&gpstates->gpstate_lock);
 
+no_gpstate:
 	/*
 	 * Use smp_call_function to send IPI and execute the
 	 * mtspr on target CPU.  We could do that without IPI
@@ -835,6 +841,13 @@  static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
 		kernfs_put(kn);
 	}
 
+	policy->freq_table = powernv_freqs;
+	policy->fast_switch_possible = true;
+
+	if (pvr_version_is(PVR_POWER9))
+		return 0;
+
+	/* Initialise Gpstate ramp-down timer only on POWER8 */
 	gpstates =  kzalloc(sizeof(*gpstates), GFP_KERNEL);
 	if (!gpstates)
 		return -ENOMEM;
@@ -849,15 +862,14 @@  static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
 				msecs_to_jiffies(GPSTATE_TIMER_INTERVAL);
 	spin_lock_init(&gpstates->gpstate_lock);
 
-	policy->freq_table = powernv_freqs;
-	policy->fast_switch_possible = true;
 	return 0;
 }
 
 static int powernv_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 {
 	/* timer is deleted in cpufreq_cpu_stop() */
-	kfree(policy->driver_data);
+	if (policy->driver_data)
+		kfree(policy->driver_data);
 
 	return 0;
 }
@@ -990,7 +1002,8 @@  static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy)
 	freq_data.pstate_id = idx_to_pstate(powernv_pstate_info.min);
 	freq_data.gpstate_id = idx_to_pstate(powernv_pstate_info.min);
 	smp_call_function_single(policy->cpu, set_pstate, &freq_data, 1);
-	del_timer_sync(&gpstates->timer);
+	if (gpstates)
+		del_timer_sync(&gpstates->timer);
 }
 
 static unsigned int powernv_fast_switch(struct cpufreq_policy *policy,